This invention relates to a building construction element in the form of a wood log with flat planed upper and lower surfaces, a longutudinally extending groove being cut into each surface to a depth about equal to half the thickness of the log, the grooves being on opposite sides of the vertical medial plane of the log and each groove being filled with a foamed plastic, such as polyurethane, having thermal insulating properties which are superior to those of solid wood. The flat surfaces may be provided with smaller longitudinally extending grooves or kerfs, in the medial plane, to receive splines for ensuring accurate assembly of vertical arrays of logs and for initially sealing the horizontal cracks between superimposed logs.
In the construction of a building wall by the superposition of prepared logs, it is desirable to increase the thermal insulating qualities of the logs themselves, because the surfaces of the wall are normally not intended to receive insulation. This invention is directed to an insulating wall log for use as a construction material in the fabrication of log homes and similar structures in which wooden logs function as both structural and insulating building materials. A principal feature of the invention is the provision of grooves cut vertically in the flat top and bottom surfaces of the log on opposite sides of a vertical plane running lengthwise along the center of the log, which grooves are thereafter filled with foamed polyurethane or the like. Optionally, spikes may be driven horizontally through the log and filled groove to stabilize the structure.
It is an object of the invention to increase the insulating capabilities of the log by removing certain portions of the wood material and replacing them with a synthetic material having superior insulating properties.
It is another object of the invention to effect such a substitution of plastic for wood without impairing the structural integrity of the log.
It is a further object of the invention to provide such a log in which there is the equivalent of a constant thickness of supplemental insulating material, without resorting to a plastic sandwich construction.
It is a still further object of the invention to provide certain improvements in the form, construction, arrangement and materials of the several features of the combination by which the above named and other objects may effectively be attained.
It is known to provide built-up construction elements resembling logs by forming a plastic sandwich, faced on each surface by a wooden plank; it is also known to seal the horizontal or vertical cracks between logs by means of plastic strips, which arrangement has little or no thermal benefits.
The invention accordingly comprises an article of manufacture possessing the features, properties, and the relation of elements which will be exemplified in the article hereinafter described, and the scope of the invention will be indicated in the claims.